Recently in such image capturing devices as digital cameras and video cameras, smaller sizes and higher performances are demanded. As a lens to satisfy these demands, a zoom lens comprising, in order from an object, a lens group having negative refractive power, a lens group having positive refractive power and a lens group having positive refractive power is widely used. For such a zoom lens, a lens system, of which weight and cost are decreased by comprising less number of lenses and using plastic lenses instead of glass lenses, is known (e.g. see Japanese Laid-Open Patent Publication No. 2008-181118(A)).
In the case of this conventional zoom lens however, the angle of view is narrow and the zoom ratio is low, even if a smaller size, lighter weight and lower cost are implemented.
Another zoom lens that is known as a zoom lens, that meets the demands for smaller size, slimmer construction and lighter weight of the camera main unit, comprises, in order from an object, a first lens group having negative refractive power, a second lens group having positive refractive power and a third lens group having positive refractive power, wherein the first lens group is constituted by only two lenses by effectively disposing an aspherical lens as a negative lens in the first lens group (e.g. Japanese Laid-Open Patent Publication No. 2005-84648(A)).
But if an aspherical lens is used for the negative lens, a manufacturing cost increases dramatically.